Murder on the Orient Express (1974)

Like many of Agatha Christie's mysteries, Murder on the Orient Express is predicated on an actual event, in this case the Lindbergh kidnapping. In the movie, everyone on board the Orient Express seems to have concluded that hateful financier Ratchett (Richard Widmark) was behind the abduction and murder of the infant daughter of a famed aviatrix.

Thus, when Ratchett is himself found murdered, everyone is suspect. Normally, the police would handle the investigation, but the train has been stalled by a snowslide halfway between Istanbul and Paris.